Transformations of Arctic sea ice are altering the ferocity of storms, the deadliness of polar bears and even the ovulation of ringed seals, according to a new report from Fisheries and Oceans Canada, the State of the Arctic Ocean.
The broad, overarching study finds changes in ocean ice are influencing habitat and animals in the country’s North in unpredictable ways. These changes, largely due to climate change, are leaving natural systems in chaos.
No Arctic system is more clearly affected — and has more ripple effects — than the ice.
A long-term trend of thinning ice is interfering with the ability of sea creatures to grow, reproduce and even survive.
Each year, some ice survives the summer’s heat and refreezes thicker and stronger the following winter. But even in the High Arctic, multi-year ice is becoming increasingly rare — there’s 40 per cent less at the end of the summer now than there was just 20 years ago.
At the same time, that old ice is thinning over the Canadian Basin at a rate of 40 centimetres every decade.
“Nearly all of that ice has been lost,” says Chris Derksen, a climate research scientist with Environment and Climate Change Canada.
None of these changes happens in a vacuum: when the ocean’s chemistry changes, when seasons get out of sync with the living systems that depend on them, “that has effects right through the food web,” explains Andrea Niemi, a Fisheries and Oceans Canada scientist and lead author of the new report.
Unpredictable ice confuses, traps animals
According to the report, in the coming decades the last of the multi-year ice will likely be found in the western margin of the Canadian Arctic archipelago in a place called Tuvaijuittuq, which aptly means the place where the ice never melts.
The islands create a natural barrier where the swirling winds and currents of the Arctic Ocean deposit the old ice.
The federal government announced in August it would create a marine protected area covering much of the coastline where the old ice ends up. While the designation can’t stop the ice from melting, it can protect the species that make their homes in, on and around the ice.
Arctic ice is one of the most important habitat features of the North. Bears, foxes, seals and birds use it as a platform for hunting and resting. Underneath the ice, fish hide and algae, phytoplankton, zooplankton and bacteria grow.
The ice can also prevent marine mammals from accessing the air, and the predators above from accessing the water, so finding the edges of the ice is important.
Inuit knowledge has documented a shift in where that critical point occurs around Baffin Island in the last decade. The ice is also becoming less predictable and less consistent, causing problems for navigation, hunting and migration.
“If the ice becomes unpredictable, then species like narwhals or belugas can be caught off guard where they can’t get out,” Niemi says.
Killer whales, drawn into the newly accessible Arctic, have also become trapped in unfamiliar ice-covered waters. “Inuit observations are noting they’re coming in more frequently,” Niemi says.
The confusing, treacherous ice conditions also leave polar bears ashore longer. Hungry bears waiting for sea ice to form still need to eat, which forces them to eat bird eggs, raid human food sources or otherwise scavenge. While bears have been eating more bird eggs, the open water that forces them ashore also allows the birds to feed more, cancelling out the bears’ negative effect on their population.
When the bears show up in communities, however, the effects are much graver.
A 2017 study found a notable increase in polar bear attacks on people in recent years. Between 2010 and 2014, there were 15 attacks compared to an average of one per year in the 50 previous years. Nearly 90 per cent of those maulings happened at the time of year when sea ice is at its lowest extent.
Just outside Arviat, Nunavut, 31-year-old Aaron Gibbons was mauled to death by a polar bear while protecting his children in 2018, one of two deadly attacks in the Kivalliq region that summer.
The unpredictable ice also presents challenges for people who rely on it for travel and hunting.
Within living memory, dog teams could run on sea ice from mainland Nunavut to Pond Inlet, on Baffin Island, in July. Today, they would be swimming through much of their voyage, according to Pond Inlet Elders who were interviewed for the government’s report.
People from other communities such as Cape Dorset and Cambridge Bay told similar stories of waiting longer for freeze-up and having less time to safely travel on the ice.
They also noted the ice itself is different: powdery, less flexible, softer — the kinds of conditions that can make it more dangerous. Falling through the ice can be fatal, and stories of travel cut tragically short are not uncommon.
“All of this impacts the traditional way of life,” Derksen says. “Communities have to adapt very quickly.”
Thinning ice leads to severe storms that speed up erosion
Sea ice has a calming effect on the Arctic Ocean, lying on its surface like a weighted blanket. When the ice thins, breaks up or disappears entirely, storms can grab hold of the water and generate towering waves.
In the Beaufort Sea, the patch of the Arctic Ocean west of Canada’s Arctic islands, storms have been getting progressively worse since the late 1990s. Winds and waves have been pummelling the shoreline around Tuktoyaktuk, Northwest Territories, causing erosion and flooding.
This erosion is threatening to send homes toppling into the sea. Sandbags and concrete slabs have bought the hamlet some time, but the sea’s march inland is inexorable: now the local government is working on relocating its residents before it’s too late.
Just 150 kilometres away, along Yukon’s Beaufort Sea coastline, enough sediment is being washed into the sea every year to fill a train 24,000 cars long. That annual erosion releases 35 million kilograms of carbon, decreasing the ocean’s ability to absorb carbon dioxide from the atmosphere and adding to the warming.
Storms can affect communities in other ways, too.
A 2016 storm over the second lowest sea ice extent on record contributed to the worst beluga hunt Tuktoyaktuk has ever seen. The storm kicked up waves that made it unsafe for hunters to leave shore. Those who did venture out may have had a hard time spotting the small whales — if they were there at all. Scientists have noted the creatures come into the estuary seeking calm, warmer waters.
Shipping, tourism take advantage of retreating ice
As the ice retreats, more shipping and tourism is making its way through the Canadian Arctic archipelago. The tiny communities nestled among the islands have seen the positive effects of more people showing up on their shores, in the form of income from tours and art sales, while they’ve also suffered negative impacts.
People fear noisy ships are scaring away narwhals and belugas, while the ships’ operators have been known to buy the local stores out of produce.
When it comes to shipping traffic, “all the risks are there for northern communities but they don’t stand to benefit from that activity,” Derksen says. Fearing oil spills and other catastrophes, Arctic communities have rushed to get training and equipment to help them respond.
Invasive species, introduced through the bilge water of ships, present a growing threat.
The threats to people and wildlife are exacerbated by a lack of scientific knowledge about biodiversity in the Arctic Ocean. In some places, scientists estimate up to 60 per cent of species — like the tubeworms living on undersea volcanoes and feeding on methane, only discovered in 2013 — are yet to be discovered.
In describing the cascading changes throughout the natural systems of the Arctic Ocean, from air currents to zooplankton, the new government report comes back to one central theme, Niemi says.
“When we talk about the changes being observed, we talk about how they can all be linked back to changes related to sea ice.”